统计字符串中字符出现的次数(Python版)

字符串转list

1s = 'aabbccd'
2list1 = list(s)

方法一：

1list1 = ['a', 'a', 'b', 'c', 'c', 'c', 'c']
2dict_cnt = {}
3for value in list1:
4    dict_cnt[value] = dict_cnt.get(value, 0) + 1
5print(dict_cnt)

方法二：

1list1 = ['a', 'a', 'b', 'c', 'c', 'c', 'c']
2dict_cnt = {}
3for item in list1:
4    if item in dict_cnt:  # 直接判断key在不在字典中
5        dict_cnt[item] += 1
6    else:
7        dict_cnt[item] = 1
8print(dict_cnt)

End

林末 https://www.helloworld.net/linmo